The way I look at it is that the CBJ have only one slot left for a big money/top 4 defenseman. Z and Severson take two of these slots. Mateychuk has a very good chance to be number 3. So the decision would be "do we want/need to commit to Provorov for 7 years at around $7 million/year"?
My answer to my question would be "no". Nothing wrong with kicking the tires and trying to get him to sign a lower money 3 or 4 year deal, but this is going to be his last big contract and it's highly unlikely that he'd bite. I sure wouldn't if I were in his shoes.
Our overall defense isn't at the level where there should be no/little room to obtain another good/large contract dman. Provorov doesn't fit the bill to me to fill the 4th slot. His play this year has been pretty good-but that's a common happening in a "contract year".
The CBJ will be best served by trading him for assets at the TDL, IMO.